1. Field of the Invention
The present invention relates to a source driver and a driving method thereof, and more particularly, to a source driver and a driving method thereof which utilize a mapping operation and an odd-number switching operation to switch the source driver being operated in two operational modes.
2. Description of the Prior Art
As technology advances, people gradually pursue higher resolution as well as thinner/smaller size of hardware devices. A conventional display device includes a plurality of transmission channels corresponding to a plurality of source drivers, such that the adjacent transmission channels marked with an odd number and an even number can be adaptively designed to share one digital-to-analog converter, and an even-number switching operation can also be applied to the adjacent transmission channels, so as to complete a driving method for the source drivers of the display device. In detail, the conventional source driver can be operated in two operational modes, as shown in FIG. 1A, FIG. 1B, FIG. 2A and FIG. 2B. FIG. 1A and FIG. 1B are schematic diagrams of a conventional source driver 10 to be operated in a first operational mode, wherein FIG. 1A illustrates a schematic diagram of the source driver 10 receiving a display information INDA_1 generated by a timing generator (not shown in the figure), and FIG. 1B illustrates a schematic diagram of the source driver 10 outputting the display information INDA_1 shown in FIG. 1A. Besides, FIG. 2A and FIG. 2B are schematic diagrams of the conventional source driver 10 to be operated in a second operational mode, wherein FIG. 2A illustrates a schematic diagram of the source driver 10 receiving a display information INDA_2 generated by a timing generator (not shown in the figure), and FIG. 2B illustrates a schematic diagram of the source driver 10 outputting the display information INDA_2 shown in FIG. 2A.
As shown in FIG. 1A, the display information INDA_1 received by the source driver 10 is a serial information and comprises display information DATA(A), DATA(B), . . . , DATA(X) and DATA(Y). As shown in FIG. 1B, the source driver 10 further comprises a shift register 100 to receive the display information INDA_1. The source driver 10 further comprises transmission channels CH[n], CH[n+1], . . . , CH[m−1] and CH[m], and each transmission channel CH[X] comprises a register 102_X, a voltage level transformer 104_X, a positive (or negative) polarization digital-to-analog converter 106_X and an operational amplifier 108_X. The register 102_X further comprises a first register unit 102_1_X and a second register unit 102_2_X. Besides, the display information INDA_2 shown in FIG. 2A is identical to the display information INDA_1 shown in FIG. 1A, and the source driver 20 shown in FIG. 2B is similar to the source driver 10 shown in FIG. 1B, wherein a difference is a connection way for two adjacent transmission channels, e.g. the first register unit 102_1_X and the second register unit 102_2_X, such that the display information INDA_1 and INDA_2 outputted by the transmission channels CH[n], CH[n+1], . . . , CH[m−1] and CH[m] of the source drivers 10 and 20 are different with two types of polarization of display sub-information.
As shown in FIG. 1A and FIG. 1B, when the source driver 10 is operated in the first operational mode and the shift register 100 has received the display information INDA_1, the source driver 10 sequentially transmits the display information DATA(A), DATA(B), . . . , DATA(X) and DATA(Y) of the display information INDA_1 to the transmission channels CH[n], CH[n+1], . . . , CH[m−1] and CH[m], and accordingly, the display information DATA(A), DATA(B), . . . , DATA(X) and DATA(Y) sequentially pass through the register 102_X, the voltage level transformer 104_X, the positive (or negative) polarization digital-to-analog converter 106_X and the operational amplifier 108_X, to be outputted as the two types of polarization of display sub-information. The first type of polarization is a positive voltage level, such as voltages V(A), V(C), . . . V(X) correspondingly being transmitted to the transmission channels CH[n], CH[n+2], . . . , CH[m−1], and the second type of polarization is a negative voltage level, such as voltages −V(B), −V(D), . . . , −V(Y) correspondingly being transmitted to the transmission channels CH[n+1], CH[n+3], . . . , CH[m].
Furthermore, as shown in FIG. 2A and FIG. 2B, when the source driver 20 is operated in the second operational mode and the shift register 100 has received the display information INDA_1, the source driver 20 sequentially transmits the display information DATA(A), DATA(B), . . . , DATA(X) and DATA(Y) of the display information INDA_1 to the transmission channels CH[n], CH[n+1], . . . , CH[m−1] and CH[m]. In comparison with the operation of the source driver 10, the first register units 102_1_X and 102_1_X+1 and the second register units 102_2_X and 102_2_X+1 of the adjacent transmission channels CH[X] and CH[X+1] of the source driver 20 have different connections, i.e. the first register unit 102_1_X is coupled to the second register unit 102_2_X+1 and the first register unit 102_1_X+1 is coupled to the second register unit 102_2_X, such that the adjacent transmission channels process a switching operation once for the display information. After passing through the second register units 102_2_X and 102_2_X+1, the display information DATA(A), DATA(B), . . . , DATA(X) and DATA(Y) are transmitted to pass the voltage level transformer 104_X and the positive (or negative) polarization digital-to-analog converter 106_X, and accordingly, another switching operation for the display information is processed before the display information DATA(A), DATA(B), . . . , DATA(X) and DATA(Y) enter the operational amplifier 108_X. Thus, the two types of polarization of display sub-information are correspondingly outputted, and in contrast with the source driver 10, the source driver 20 outputs the first type of polarization as a negative voltage level, such as voltages −V(A), −V(C), . . . , −V(X) to be correspondingly transmitted to the transmission channels CH[n], CH[n+2], . . . , CH[m−1], and the second type of polarization as a positive voltage level, such as voltages V(B), V(D), . . . , V(Y) to be correspondingly transmitted to the transmission channels CH[n+1], CH[n+3], . . . , CH[m].
As can be seen in FIG. 1A and FIG. 2A, although the source drivers 10 and 20 receive the same display information, the corresponding voltage levels outputted by the positive (or negative) polarization digital-to-analog converter are exactly opposite, i.e. the transmission channels CH[n]-CH[m] of the source driver 10 sequentially output a plurality of voltage levels as V(A), −V(B), V(C), −V(D), . . . , V(X) and −V(Y), and the transmission channels CH[n]-CH[m] of the source driver 20 sequentially output a plurality of voltage levels as −V(A), V(B), −V(C), V(D), . . . , −V(X) and V(Y). Due to different operational modes, the source drivers 10 and 20 are necessary to utilize two (or even numbers) switching operations for the display information, so as to output different polarizations of the display information for different transmission channels. After receiving a plurality of display information, conventional operations of the source drivers 10 and 20 are necessary to first determine what kinds of the operational modes are, so as to adjust/switch connections of a plurality of register units of every two adjacent transmission channels, which leads less flexible applications. Therefore, it has been an important issue to provide another flexible design and driving method for the source driver utilized for a display device.